Associations between the keratinized mucosa width and the underlying alveolar bone dimensions at partial edentulous molar sites: a retrospective cross-sectional study

Abstract

Abstract Background The assessment of hard and soft tissue at edentulous sites is important for subsequent implant treatment design. The aim of the present study was to explore the associations between the keratinized mucosa width (KMW) and the underlying alveolar bone dimensions at partial edentulous molar sites. Methods In this retrospective study, a total of 110 patients with at least one missing molar were selected. The buccal KMW of the edentulous molar sites was evaluated. Cone-beam computed tomography scans were collected, and the height discrepancy between the alveolar crest and the buccal bone plate (HC−B) as well as the alveolar bone height (ABH) were measured. The KMW was compared among the HC−B and ABH groups at both maxillary and mandibular sites. Linear regression and generalized estimation equations (GEEs) were used to explore the associations between the KMW and alveolar bone dimensions at α = 0.05. Results Among the 110 patients, 158 edentulous molar sites were analyzed. The average HC−B and ABH were significantly lower at the maxillary sites (1.26 ± 1.62 mm, 11.62 ± 3.94 mm) than at the mandibular sites (3.67 ± 2.85 mm, 14.91 ± 3.01 mm, p 2 mm than at sites with HC−B ≤ 2 mm both in the maxilla and mandible (p 0.05). Linear regression and GEEs analyses revealed that the HC−B was significantly associated with the KMW (B = -0.339, p < 0.001), while the association between the KMW and the ABH was not statistically significant (B = -0.046, p = 0.352). Conclusions The buccal KMW at edentulous molar sites was significantly associated with the HC−B. Alveolar ridges presenting with a sloped configuration were more prone to possess a narrower band of keratinized mucosa. Both hard and soft tissue augmentation should be considered for implant treatment at these sites. The correlations of dynamic changes between the KMW and alveolar bone dimensions after tooth extraction should be further investigated.

Keywords

• Alveolar process atrophy
• Alveolar ridge
• Buccal mucosa
• Cone-beam computed tomography